join us for cbs 5 early edition ... beginning at five. ,,,, >>> on the "cbs morning news" here's a look at today's weather. the east coast will get more much-needed rain. showers will hang around the great lakes area, and the west continues to see warm temperatures. the southwest can see another round of record-breaking heat. >>> here's another look at this morning's top stories. cbs news has learned that white house chief of staff rahm emanuel is likely to leave the obama administration to run for mayor of chicago. an official announcement is expected by friday. >>> and president obama is in the midst of a four-state campaign swing, hoping to rally democratic voters. the president is visiting new mexico, wisconsin, virginia and iowa. >>> the midterm elections ece only five weeks away. for candidates in tight races, negative ads are increasingly the weapon of choice. nancy cordes reports. >> -- to pay taxes on $14 million. >> reporter: with the political wind blowing against them, democrats aren't just going negative, t